If your SATA controller is a bootable controller (the vast majority are) you may boot from the SATA drive. You may need to enter Setup and change the boot sequence so that the SATA controller is the first boot device listed. In most cases, if the SATA controller is embedded (not an add-on controller card) on the motherboard, the BIOS Setup utility will have an option to choose the SATA drive as the first boot device. Look for Boot Sequence, Boot Options, Boot Order or a similar setting to make this change. If Setup does not allow this change, your system BIOS may not allow the SATA controller to be designated as a boot device at the BIOS level. In such cases, you still may be able to boot to the SATA drive as long as there is not a bootable EIDE drive installed in the system as well.
Note: When installing Windows 2000/XP to a Serial ATA drive, you may need to specify the SATA controller drivers early on during the installation.